The present invention is directed to a digital to analog converter with improved companding.
In the telephone art in pulse code modulation (PCM) systems, digital to analog converters are required for converting to PCM from a sampled analog signal and thereafter reconverting back to an analog signal. A typical PCM signal consists of eight bits which represent 256 different amplitude levels.
During the above conversions, it is desirable to provide a standard companding characteristic to improve the signal to distortion ratio of speech. Past techniques have introduced excessive errors. In addition, any change in the companding characteristic was very difficult to make.